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The crystal structure and thermoelectric properties of La(Fe1-xSix)13 compounds were investigated by means of X-ray powder diffraction and electrical resistivity, thermopower and thermal conductivity measurements. The single NaZn13-type cubic structure phase is stabilized for the compounds with x = 0.12, 0.14 and 0.15. These magnetic phase transitions are also seen in the electrical resistivity, thermopower and thermal conductivity measurements. All compounds have the small values of thermopower and lattice conductivity. . | VNU Journal of Science Mathematics - Physics 25 2009 193-197 Synthesis and thermoelectric properties of La Fe1-xSix 13 compounds x 0.12 0.14 and 0.15 Do Thi Kim Anh1 Makio Kurisu2 1 Faculty of Physics College of Science VNU 334 Nguyen Trai Thanh Xuan Ha Noi 2 Japan Advanced Institute of Science and Technology School of Materials Science Nomi Ishikawa 923-1292 Japan Received 2 October 2009 Abstract. The crystal structure and thermoelectric properties of La Fe1.xSix 13 compounds were investigated by means of X-ray powder diffraction and electrical resistivity thermopower and thermal conductivity measurements. The single NaZn13-type cubic structure phase is stabilized for the compounds with x 0.12 0.14 and 0.15. These magnetic phase transitions are also seen in the electrical resistivity thermopower and thermal conductivity measurements. All compounds have the small values of thermopower and lattice conductivity. However thermal conductivity is large. Keywords Thermoelectric Itinerant-electron metamagnetic IEM keywords. 1. Introduction The magnetic properties of LaT13 T Fe and Co compounds of the NaZn13-type cubic structure have been intensively studied. These compounds have the largest amount of transition metal in the crystalline formula unit among the rare-earth transition intermetallics 1 2 . The cubic NaZn13-type structure is easily stabilized in the binary La-Co compound. For the La-Fe compound this structure can be formed only in pseudo-binary La Fe1-xMx 13 M Al Si compounds 3 . The magnetic state in La Fe1-xAlx 13 compounds is ferromagnetic for 0.14 x 0.38 and antiferromagnetic for 0.08 x 0.14 4 . La Fe1-xSix 13 compounds are ferromagnetic in the region 0.14 x 0.38. However their Curie temperature TC decreases with increasing Fe concentration whereas the saturation magnetic moment increases 1 . For these La Fe1-xSix 13 compounds it was reported that in the high Fe concentration region an itinerant-electron metamagnetic IEM transition i.e. a field-induced .
